Document settings

[sbabcoc]

This should mostly be just a copy/paste/format task, because the settings enumeration includes JavaDoc for each setting.

[sbabcoc]

The existing documentation includes descriptions of many of the settings interspersed within the text, but there's no single comprehensive list of available settings. The page I'm visualizing here will document all of the settings and include links to the related feature descriptions.

I also need to properly document the new GRID_PLUGINS setting. I just did a slapdash job on the Configuring Project Settings page, which is the wrong place for this information. This needs to be moved to the Local Grid Configuration page and expanded.